Bidding Options:Per Cutting, Monthly, or Mowing Season???

I did a little searching, and didn't find anything that covered my question. I'm thinking of commercial or non-residential properties here. There are three churches within a couple of miles of my home, and all have probably a couple of acres of green stuff. I would like to have a shot at getting at least one of them, but don't know whether to bid on a per cutting basis, or give them a monthly or seasonal rate, billed monthly. What is the opinion of some of you guys with more experience? Thanks, Neill.

I bid on a church for the coming season through one of my residential customers who is involved there. I gave them a per mow price and would bill them monthly. I don't have alot of experience in the commercial/non-residential area..but that's what I did! ps. season isn't quite here yet so I haven't heard back!! Z